Process of making briquets.



o'r'ro meters, or osn'auut' cn, durum.

lt rlt l l l l PROCESS 015' MAKING Blllflflh'lllltl.

l lo Drawing.

Specificotion of Letters remit.

lltzitented Ploy. it 1 1.,

substance here'i i-aittcr more particularly described and referred to asfilter dust, is capal'ile of developing an unusual capacity as a binder,particularly for ore briquets when briquets containing such filter dustare treated with steam under pressure.

The filter dust which is the specific ma terial to which thisapplication is directed is the dust caught by the filters in furnacepractice in which solid particles are eliminoted from the furnace gasesby means of what is know as the dry process such as is described forinstance in German Patent No. 250,394: as distinguished from the wellknown wet process in which after the fine dust proper has settled out ofthe furnace gases, the latter are passed through wet catchers in whichthe remaining; dust settles as a mud or slime. Neither the flue dustproper (for reasons explained below) nor the slime even when dried arecontorw plated as the binding medium of this application since I amconcerned solely with the fine dry particles which are caught by thefilters in a process in which the addition of excessive moisture to thefurnace gases is avoided in the treatmentof these gases after the fluedust proper has settled from them and before, the come into contact withthe filters.

The particular substance with which ll am concerned is known in the. artare filter dust which is a dust in a state oi extremely finesub-division, so line that it floats along with the furnace gaseswithout bein' separated from them when the flue dust proper isprecipitated or caught. This fine filter dust contains very little ironbut 'is apparently composed in the main of silica. (sioo, alumina (A1 0and lime (GaO). According to one theory "this filter dust is created bymeans of the vaporization which takes place at the twyers of the blastfurnace, at the place Where the highest temperature pro-- veils.According metals silicon, aluminum .a.nd calcium are supposed to existin the Zone oi the hi temperatures in the form of elements, being due LOthe reducing atmosphere, these elel'nents are considered when they thisfilter dust which is cauried away by the furnace gases and is recoveredin the final ltering operation as employed till the dry process.

ll hate'ver inoy he the exact chemical coinposition of the filter dust,it is a substance which is passed thmugh the blast. furnace and has beensubjected therein to the blast furnace conditions as much as fine dust.lhe filter dust.however dift'ers radically from fine dust. A givenquantity of tilte 3 dust has been analyzed as containing the following);

to another theory the I ingredients in the following percentages: Sit)29 ilrl ,U 20 Yo, Cal QYI/U, Fe-+i%. lit also contained in small pencentage magnesium oXid, potassium oxid etc. Flue dust on the otherhandis substantially a reduced iron containing from lO to of iron, and10 to 20% cerbon. Flue dust may thereikire generally be consideredfrictional. disintegration. lhe filter dust on the other hand cannot beconsidered as ore but it it; is to be given it general class fied-- tionmay he classified as a relatively poor in lime. it is, of course, asexplained, not really a slug but a composition prob-- ably of manyingredients, the entire composition being peculiar to itself due to themanner of its creation. This lilter dust has heretofore been disposalhas been a source of diiiiculty and expense. According to experienceprior to this invention this filter dust could operate as ballast onlybut l have now discovered that it possesses a most remarkable and. tonishing faculty of causing; cohesion in a. briqii'et when treated withsteam under pres sure. I have discovered that a briquct ur ne posed cia. mixture oil line ore and the. ldce generally called lines. and thedry sue:- dust will, it simply mixed Without any special previoustreatment produce briquets of very considerable rigidity or firmnesswhen they are treated with see-am under pressure. Considering the filterdust 518 a. binder l: have small a percentage as 5 to 10% of thehinder,briquots can bomede which satisfy all the trequireiuents oi; o briquetin. blast furnace as a partially reduced iron produced by Applicationfiled August '5, 1913. Serial lite. 7633,?51. l

meet with oxygen to burn up so as to create considered a practicallyuseless product and in fact its removal or lltltl found that even withthe addition. of so lilll operation. In other were? paoity of filter Auhardening" of the steam: Hilda? (lush develops with steam undo covery offeet beoaus that 1 "is WlllCll 2 V3 ogeretions either alone Tl eke oresand such ores j considered to con- 5 Slllfiflfo ihe Ioork of whichbriouets edr 1g separated m peroime, would peeity to act as e,

,copeoiw eligehe star fact with the damp ih fi uses to which riquets erem'bendeol are primarily s are oonneoted' with smelting or frneoeopeeetioos so that the body 60 met .siel of tile briquel si s amaterial which ihe process ofbz u me is o t high tugee such as are emin,practice. "The 01" 1 ployecl in blast furnaces. to be brioueeeeli 1 Itis ofoourse obvious'thet other binding mixing maooin e with M1 in roelie, ea; be employed in addition to the 66 mixture is then bi'iqueied orpressed intot e I filter dust and such practices are ineludeol desiredshopes end; wieh the desired pressure. I Within the scope of the claim,so long as the hose briquete igllus made are placed upon fi er dust andthe steam treatment of the What are lmown as hardening wagons and Iriqn'ts are made use of. v are then cause to become hardened with "What1' c aim is: 70

steam under pressure in hardening kettles, The proeess of makingbriquets composed such for example as employed in the in the one ores orbody mefiteriel' manufacture of ealciums and stone, and after whichconsists in mixing said body material a few hours are thereby convertedinto with a perceneage of filter dust, briquefing briquetscapable of usein a blast furnace. the niziure treetiog'he briquets formed .5-

.l e foregoing pz'ocess great dvan of said mixture with sieem underpressure. tages over those heretofore known, bei g In iestimony whereofI have hereunto set extremelyelmple in operation and employ my hand inthe presence of twosubscribing ing, as it does to efi ecb the bin-clingtogether Witnesses. of the ore, 2; material which has been heretoforetotally discarded and breated as a Wasfla product 01' :firnace "orks.

he rmarkeble binding capacity of the filter dusi may of course beavailed of in OTTO Kl'PPE. Witnesses:

imowzo ABNER, ERNST H. L. MUNNENHOFF;

